The main reasons for the decrease of grinding force are the impact force,the change of material hardness and the application mode of ultrasonic vibration.On the basis of ordinary grinding,the grinding force affect mechanism of adding two-dimensional ultrasonic vibration was analyzed.Under the same grinding parameters,the comparative experiments of ordinary grinding and two-dimensional ultrasonic vibration grinding of alumina ceramics were carried out.The effects of workpiece feed speed,wheel linear speed and grinding depth on grinding force were analyzed.The results show that the normal and tangential grinding forces of two-dimensional ultrasonic grinding are less than those of ordinary grinding,the reduction amplitude of the grinding force decreases with the increase of the workpiece feed speed and the wheel line speed,and increases with the increase of the grinding depth;the normal and tangential grinding forces of ordinary grinding and two-dimensional ultrasonic grinding increase with the increase of workpiece feed speed and grinding depth,and decrease with the increase of wheel linear velocity.